diff options
Diffstat (limited to 'vendor/github.com/Microsoft/hcsshim/internal/wclayer/exportlayer.go')
-rw-r--r-- | vendor/github.com/Microsoft/hcsshim/internal/wclayer/exportlayer.go | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/vendor/github.com/Microsoft/hcsshim/internal/wclayer/exportlayer.go b/vendor/github.com/Microsoft/hcsshim/internal/wclayer/exportlayer.go new file mode 100644 index 000000000..d43e941ee --- /dev/null +++ b/vendor/github.com/Microsoft/hcsshim/internal/wclayer/exportlayer.go @@ -0,0 +1,68 @@ +package wclayer + +import ( + "io/ioutil" + "os" + + "github.com/Microsoft/go-winio" + "github.com/Microsoft/hcsshim/internal/hcserror" + "github.com/sirupsen/logrus" +) + +// ExportLayer will create a folder at exportFolderPath and fill that folder with +// the transport format version of the layer identified by layerId. This transport +// format includes any metadata required for later importing the layer (using +// ImportLayer), and requires the full list of parent layer paths in order to +// perform the export. +func ExportLayer(path string, exportFolderPath string, parentLayerPaths []string) error { + title := "hcsshim::ExportLayer " + logrus.Debugf(title+"path %s folder %s", path, exportFolderPath) + + // Generate layer descriptors + layers, err := layerPathsToDescriptors(parentLayerPaths) + if err != nil { + return err + } + + err = exportLayer(&stdDriverInfo, path, exportFolderPath, layers) + if err != nil { + err = hcserror.Errorf(err, title, "path=%s folder=%s", path, exportFolderPath) + logrus.Error(err) + return err + } + + logrus.Debugf(title+"succeeded path=%s folder=%s", path, exportFolderPath) + return nil +} + +type LayerReader interface { + Next() (string, int64, *winio.FileBasicInfo, error) + Read(b []byte) (int, error) + Close() error +} + +// NewLayerReader returns a new layer reader for reading the contents of an on-disk layer. +// The caller must have taken the SeBackupPrivilege privilege +// to call this and any methods on the resulting LayerReader. +func NewLayerReader(path string, parentLayerPaths []string) (LayerReader, error) { + exportPath, err := ioutil.TempDir("", "hcs") + if err != nil { + return nil, err + } + err = ExportLayer(path, exportPath, parentLayerPaths) + if err != nil { + os.RemoveAll(exportPath) + return nil, err + } + return &legacyLayerReaderWrapper{newLegacyLayerReader(exportPath)}, nil +} + +type legacyLayerReaderWrapper struct { + *legacyLayerReader +} + +func (r *legacyLayerReaderWrapper) Close() error { + err := r.legacyLayerReader.Close() + os.RemoveAll(r.root) + return err +} |